1. Field of the Invention
This invention relates to a lock core, particularly to one having a plurality of recessed holes bored in the recessed hollow of an upper lock cover for respectively receiving at least one steel ball therein. Thus, when a burglar employs an electric drill to break and unlock a lock by drilling through the keyhole of the lock, the steel balls in the recessed holes can stop the electric drill from drilling forward, having excellent effect of anti-theft.
2. Description of the Prior Art
A conventional lock core 1, as shown in FIG. 1, is composed of a lower lock cover 10, a lock plate 11 and an upper lock cover 12. The lower lock cover 10, the lock plate 11 and the upper lock cover 12 are respectively formed with a curved groove passage 13 matching with one another. The lower lock cover 10 is formed with a recessed hollow 14 at the upper portion and a keyhole 15 at one end. The upper lock cover 12 is bored with a plurality of pinholes 16 in the groove passage 13 for pins 17 to be respectively inserted therein. In assembling, the lock plate 11 is first deposited in the recessed hollow 14 of the lower lock cover 10 and then the upper lock cover 12 is covered on the lock plate 11, letting the groove passage 13 of the lower lock cover 10, the plate 11 and the upper lock cover 12 aligned to one another. Lastly, a clasp 18 is engaged in the corresponding clasping holes 19 respectively provided at the opposite ends of the lower and the upper lock cover 10, 12 to finish assembly of the lock core. However, such a conventional lock core 1 is easy to be broken by an electric drill, which a burglar employs to drill through the keyhole 15 of the lock.
The objective of invention is to offer a lock core able to guard against being broken by an electric drill drilling through the keyhole of a lock.
The feature of the invention is that an upper lock cover has its recessed hollow provided with a plurality of recessed holes respectively fitted therein with at least one steel ball.